Fortunato et al. showed a reduction in serum SDF-1α in patients after MI, although higher levels were associated with more adverse events,[14] and Damas et al. demonstrated a significant reduction of plasma SDF-1α in patients with stable and unstable angina compared to healthy controls.[33] The investigation of SDF-1α as a biomarker is confounded because the aforementioned studies use the commercially available ELISA from R&D Systems that employs the monoclonal mouse IgG, MAB350. The gene discussed is CXCL12; the disease is angina unstable.